Closure operator



Dec. 25, 1956 H. L. STAVENAU ET AL 2,775,446

- CLOSURE OPERATOR Filed July 7, 1955 e Sheets-Sheet 1 INVENTORS flARowLJTm Emu DAN A/l PARA MW W l4 TTORN E YJ' Dec. 25, 1956 H. L. STAVENAU ET AL 2,775,446

CLOSURE OPERATOR Filed July '7 1955 6 Sheets-Sheet 2 ATTORNEY:

u 5* U m MM i WWJ i N MWRW! V 7% ms. M m W. o R mwfi B N m m\\ \S 6 Shets-Sheet s 1 N VEN TORS Arron/vs v.5-

DA/v M PARK HAROLD L STAVE/VAU 5a in Q3 Dec. 25, 1956 H. 1.. STAVENAU ET AL 2,

CLOSURE OPERATOR Filed July '7, 1955 6 Sheets-Sheet 4 HALF OPEN IPas/r/o/v 25 ZGL/ToP) FULL OPEN POSITION U. a my H WW5 M AA 0 T i L WW Z w? B n /.g

Dec. 25, 1956 H. L. STAVENAU ET AL 2,775,446

CLOSURE OPERATOR Filed July '7, 1955 6 Sheets-Sheet 5 TOP PLATE 48B TOP TIER MIDDLE BJTTOM BUTTOM U 54L 4, zen/TOP) 26L (BOTTOM) 2s L/roP) IN VEN TORS finkow L 51A VEN/4U 8 -DAN PARK 7 dfiw ATTORNEYS .illustrative embodiments of the CLOSURE OPERATOR Harold L. Stavenau, Mankato, and Dan M. Park, ,Shakopee, Minm, assignors to Truth Tool Company, Mankato, Minn., a corporation of Minnesota Application July 7, 1955, Serial No. 520,555

19 Claims. (Cl. 268-104) This invention relates to closure operators and more especially to manual operators for opening and closing windows, doors, hatchway closures and the like, where the primary purpose of the opening is ventilation rather than access. A principal field of usefulness of the invention is as-a window operator for canopy, and outwardly opening casement windows of dwelling houses. Window operators heretofore in common use for such purposes have been in two main classes, i. e., the slide-bar type and the crank type. Each is subject to many disadvantages. The slide-bar type, while economical to make, has had the disadvantage of unsightliness, undue projection into the building during partial opening and lack of adjustability,

or alternatively, cumbersome mode of adjustment. The

crank types, while being more attractive in appearance, have the disadvantage of high cost and lack of strength and, in addition, poor adaptability to the modern canopytype windows.

It is an object of the present invention to provide an improved closure operator mechanism free from the aforesaid objections of the prior commonly used devices, and in addition to provide strong and durable mechanisms which can be manufactured at low cost for operating canopy windows, outwardly opening casement windows and the like.

It is a further object of the invention to provide an improved but inexpensive window operator for canopy and casement windows.

It is another object of the invention to provide a closure operator of great strength and holding ability, capable of securely holding the window when in the closed position, yet capable of being detachably manipulated to allow extreme positioning of the window for cleaning, servicing, application or detachment of storm windows, and the like.

It is a further object of the'invention to provide a do sure operator of simple construction, durably made and capable of long life, and in which such parts as are necessarily exposed are of functional simplicity and comely appearance.

Other objects of the invention are those inherent in the apparatus herein illustrated, described and claimed.

To the accomplishment. of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain invention,.these being indicative, however, of but afew of the various ways in which the principles of the invention may be employed.

The invention is illustrated with reference to the drawings wherein: i V

Figure 1 is an elevational view of a modern canopytype window, shown from the inside and opened, and having the closure operator of the present invention attached to it. T i i Figure 2 is a vertical-sectional view of the window and operator of the present invention, this view being taken along the line and in the direction of arrows 2-2 of Figurel. v

2,775,446 Patented Dec. 25, 1956 ice Figure 3is a generally horizontal sectional view of the window and operator, taken along the line and in the direction of arrows 3-3 of Figure 2.

Figure 4 is an enlarged, fragmentary, plan view of the operator mechanism, partly broken away. In this figure the mechanism is shown in full lines in closed position (window closed). In addition the operator handle and link portions of the mechanism are shown in dotted lines for the half open and full open positions.

Figure 5, also an enlarged, fragmentary plan view, corresponds to Figure 4, and in addition the mechanism is shown in the full open position.

Figure 6 is an enlarged fragmentary elevational view, showing the operator mechanism from the inside of the building. This view is taken along the line and in the direction of arrows 6-6 of Figure 4.

Figure 7 is a vertical transverse sectional view, taken along the line and in the direction of arrows 77 of Figure 4. f

Figure 8 is a vertical sectional view taken along the line and in the direction of arrows 8 -8 of Figure 4.

Figures 9 and 10 are related fragmentary vertical sectional views taken along the line and in the direction of arrows 910 of Figure 4. Figure 9 is partly broken away and'illustrates the mechanism in the closed position, whereas Figure 10 shows the same mechanism in the half open position.

Figure 11 is an enlarged fragmentary vertical sectional view, for illustrative purposes, and shows how the operator mechanism may be detached when the window is open, thereby allowing extreme movement of the window to the dotted line position of Figure 2, for cleaning, servicing storm sash, painting, etc. This view is related (for explanation of operation) to the views in Figures 2 and 7.

Figure 12 is a horizontal section through a typical casement window, illustrating a modified form of operating mechanism of the present invention mounted for operating said window.

Figure 13 is a fragmentary enlarged sectional view taken in the direction of arrows 13-13 of Figure 12.

Throughout the drawings the same numerals refer to corresponding parts.

Referring to the drawings, Figures 1-3 illustrate a typical modern canopy Window generally designated 10 which is made and sold, mounted in' its frame, generally designated 11. The window is attached to the window frame at the upper side portions of the window (indicated at 12) by means of a sliding connection, not illustrated, of which there are several forms in use. The slidable connection in effect provides a vertical track or groove vertically along the upper side portions of the window frame and the Window is provided with a co-operating pin or other device 12 which not only slides vertically but is also free to journal in the track. By this means the top Window member 10A is permitted to move from the full line position of'Figure l2, downward to any desired position within the limits provided. The window 19 is stabilized and braced by radius rods 14-14 at each side of the Window. The radius rods serve to provide a pivotal path of motion for the pivot points 1515 at opposite sides of the window and hence as the top portion of the window moves downwardly, the plane of the window is swung out. t i

The usual degree of movements are shown in Figure 2. These include the closed position, shown in dotted lines and any degree of opening movement to and including the full open position shown in full lines. This range of movement iswhat is accommodated by the window operating a mechanism during normal movement. However, the window may be unhooked from the windowoperating mechanism and be'moved further to the servicing position for window washing, servicing storm windows, etc. It is noted parenthetically that the storm sash, in this design, is a thin metal edged sash and is mounted against the outer face of the window as denoted at SS in Figure 2. The details of canopy window construction vary somewhat but the general configuration and the motions are approximately as here illustrated. The details of the window construction do not, per se, form a part of the present invention except as they may be necessarily included in the novel combinations claimed.

One representative form of our closure operator mechanism of the present invention is shown applied to the window and frame of Figures 1-3. In general the mcchanism comprises a frame assembly, generally designated 20 on which a crank drum 21 is mounted for rotation on pivot pin 22. The crank drum is rotated by a lever arm 23 having knob 24 thereon. On the frame assembly there are two pivots 25L and 25R upon which the lever arms 261. and 26R are adapted to swing. Within the frame assembly 20 there are provided mechanical linkages (which will be described) by means of which the arms 26L and 26R are swung simultaneously toward or away from each other by swinging the crank-lever knob assembly 21- 23 24.

At the outer ends of each of the levers 26L and 26R there are pivots 27L and 27R to which the proximate ends of links 28L and 28R are pivotally attached. The distal ends of the links 28L and 28R are in turn each pivotally attached at pivots 29L and 29R to a clip bar 30 which has an elongated slot 31 in it. The slot 31 is fashioned so as to receive the hook generally designated 32 which has a reach portion 32R, and an upturned tip or hook end 32H. Hook 32 is fastened to the outwardly movable (and in Figures 2, 7 and 11 the lower) window frame portion B by screws 34 having round or other protuberant heads 34H. The shaping and size of the bar 30, slot 31 and hook 32, and the size and position of the screw (or other fastener) heads 34H is of some importance, since the screw head 34H will, in the Figure 7 position of the parts, serve as a stop to prevent direct upward movement of the bar 30 and thus prevent its intentional or unintentional displacement of bar 30. Yet when the window opener mechanism is operated so as to bring the window and operator parts to the positions shown in full lines in Figure 2, the consequent tilting of the hook 32 relative to the bar 30 will permit sufficient clearance to allow lifting of the bar 30 to the position shown in dotted lines in Figure 11, and its disengagement from the hook 32, which is consequently freed. The window can then be brought down manually to the servicing position shown in Figure 2. To re-engage the window operating mechanism the procedure is reversed. The shape of the hook 32, bar 30 and the size and position of the screw heads 34H are selected so as to permit separation of the bar 30 from the hook 32 only when the window has been moved to at least a partially opened position.

The pairs of arms 26L-28L and 26R and 28R provide what may be denoted as a scissors movement. The linkage is strong and durable. The elongation of the slot 31 in bar 30 and generous width of hook end 34H stabilizes bar 30 against rotation about any generally upright axis but rotation is permitted about an axis parallel to the slot 31 (see Figures 2, 7 and 11), thereby permitting rotation of the hook 32 coincidental to the changing plane of the window 10 as it is opened or closed.

It will be noted that the change in elevation of the hook 32 as the window is opened will cause an upward simultaneous flexure of the scissors-arm pairs MEL-28L and 26R-28R. The flexibility of the material of which these parts are made permits this. The resultant extra downward tension of the scissors arms on the hook 32 (and window 10), when the window is in the full open position (see Figures 2 and 11) will provide additional stability for the window against movement or rattling when it is wide open. This is an advantage, and is a feature of the invention.

The internal mechanisms of the frame assembly 20, by which the foregoing window operating motions of the device are accomplished, will now be described. Referring particularly to Figures 48, the frame mechanism includes an upper frame plate 41 and a lower frame plate 42. For reducing manufacturing costs these are preferably made identical. In the illustrated form, each plate has the shape as for plate 41 in Figure 5, as follows: Towards the inside of the building an edge 41A through to 41D. Midway between these points the edge is preferably indented marginally as at 41B to 41C, to allow space for a small vertical insect-guard plate 43 to slide from side-to-side, as shown in Figures 9 and 10. From point 41D the edge of plate 41 continues forwardly toward the front edge 41F 41G which is preferably parallel to the window portion 10B but spaced sufiiciently therefrom to allow bar 30 and hook 32 (plus a little clearance) when the window is fully closed as shown in Figure 4. ln the illustrated form the plate 41 is cut off at 45 at corners 41E41F and 41G41H, but this is not an essential. Plate 41 (and 42) each are provided with a rearwardly extending tongue as at 41] for plate 41, which is smoothly rounded at the front end 41K and provided with a pivot hole 41L which serves to receive the pin 22 upon which crank drum 21rotates.

In addition the plates 41 (and 42) each have holes, as for plate 41, as follows: Two spaced holes 41M and MN which receive pivot pins 25L and 25R respectively, upon which the arms 26L and 26R respectively, are pivoted; hole 411 through which a back mounting screw 46 is placed and two holes HQ and 41R through which screws 47 which hold the frontbracket plate generally designated 48, can entirely pass. Note that when the mechanism is operated to the Figure 4 position the screws 47 can be placed and a screwdriver inserted for tightening them. In addition plates 41 and 42 have slots, as for plate 41, as follows: Three spaced parallel fore and aft slots 418, 411 and 41U. .The middle slot 41U is displaced inwardly.

The front bracket plate 48 has a rearwardly extending foot 48A and a vertical front surface 48B. The foot is punched appropriately to locate the holes for screws 47 immediately below the holes 41Q41R of plate 41, when the vertical surface 48B of plate 43 is in contact with the front edge line 41A41D and plate 48 is aligned laterally. The front 48B is provided with a rectangular hole 48C which permits tongues 41] and 421 to pass therethrough. The rectangular slot has an extending notch 48D at the left side to allow clearance for link 50.

The plates 41 and 42 are thus positioned and spaced. At their rear edges plates 41 and 42 are held by the screw 46, the plates being held apart by sleeve 49.

The laterally extending notch 48D accommodates connecting link 50 which has its rear end pivoted at pins 51 in the crank drum 21 and at its forward end has afiixed to it a vertical front pin 52 which is long enough to extend into and hence slide forwardly and rearwardly in the slots 41U and 42U of plates 41 and 42, respectively. Hence the rear end of link 50 has a sidewise movement at its middle and rear ends.

Of course, the link 50 and tongues 41J42J do not entirely fill the rectangular hole 48C and to close off the unfilled space there is provided the little slidable insect guard plate 43. It has three slots but here the centre slot 43B is punched so as neatly to fit around the link 50, and the upper and lower slots 43A and 43C respectively have lengths sufficient to allow the plate to move sidewise to and fro, between the positions shown in Figures 9 and 10. The indented edge at 41B41C of plate 41 (correspondingly for plate 42) allows enough space for the thickness of plate 43 to slide edgewise. The action of plates 43 and 48 in co-operation thus always provides a closure which iscomplete against insect entrance. It may be stated parenthetically that the insect screen is placed in the space between lines 11A and 11B tog-memes (seeFi'gure 2')- and'the lower edge' of th'e'rscreenr franie is notched so as to fit over the window operatoriframeas- .are in the top and bottom tiers. Thus, as shown in Figures 4, 5 and 6 there are a top and bottom pair of arms'26L (top) and 26L (bottom) which together make up the arm 26L. These pivot as a unit on tubular pin 25L which is turned to provide a spacing collar 25L at its middle, for holding the arms apart by a distance equalling the thickness ofth e middle tier, plus working clearance. Similarly the arm 26R is composed of a top piece 26R (top) and an identical bottom piece 26R (bottom) which similarly pivot ona collared hollow pin 25R (collar 25R). Then at the inner end of each of the arms 26L and 26R is provided a hollow pinpivot (roll pin) as at 54L (for arm 26L) and 54R (for arm 26R). These pivot-pins are'long enough to extendfrom the upper surface of lower frame plate 42 to the under surface of upper frame plate 41. To these pins there are respectively attached the inner end of drag links SSL and 55R, both of which reside in the middle tier. These drag links are of identical length and extend forwardly (as shown in Figure 4) and each is provided with a hollow pivot pin (roll pin) as at 56L for link 55L and 56R for link 55R. Pins 56R and 56L- are of a length such that they reach from the bottom surface of lower frame plate 42 to the top surface of upper frame plate 41 and their upper and lower ends reside in and move back and. forth in the matching slots of the upper and lower frame plates. Thus pin 56L works in the matching slots 415-428 and pin 56R works in the matching slots 41T42T. Thus pins 56L and 56R follow straight line paths foreandaft, whereas pins 54L and R follow arcuate paths. The motions of the links SSL and R are defined by these straight and arcuate paths of the pivot pins. 7

In the upper and lower level tiers and pivotally connected to the pins 56L and 56R are an identical (upper and lower) pair of bent single-tree levers 57T and 57B. These each have a pivot hole at the middle to receive a hollow pivot pin 52, which is of a length such that it reaches from the lower surface of lower frame plate 41 to the upper surface of upper frame plate 42. Pin 52 connects the front end of connecting link 50 (which is in the middle tier) to the center point of each of the bent levers 57T (top) and 57B (bottom). The, upper and lower ends of pin 52 work back and forthin the middle slots 41U and 42U of the bottom and top frame plates.

The crank drum 21 has slots extending straight across at the levels of the top and bottom plates and the middle tier. The slots extend more than half way throughrthus (see Figure 4), from point 21A around the arc21A, 21B,

21C to point 21C, thence back across the chord 21C- 21A. Each slot is wide enough to accommodate with clearance the plate or tier component extending into the slot. Thus (see Figure 7), tongues 41;! and 42] fit neatly with working clearance into the appropriate top and bottom slots of the crank drum. The pivot 22 of the drum is made in two pieces and does not extend across the middle slot (see Figure 7). When the handle 23-24 is swung arcuately in the direction of arrow 59 from the full line (closed) position the pivot 51 will traverse the path of arrows 60-61 through the half open to the full open position of Figure 5. In so doing the link 50 will be pulled in a direction away from the window (downwardly in Figures 4 and 5) and this then pulls the pair of (top and bottom) bent levers 57T 'and57B correspondingly and these in turn push back on links SSL and R and cause the arms 26L and 26R to swing in the pair 26L-28L is retained.

'diICCfiOlTOfJdITOWS 63:'and 64,-respectively. This propels 'thelinks,28L and 28R forwardly and together (at their rearward ends) from position of Figure 4 to position of Figure Sand the window is opened. All forces are balanced in the thus, described motions. The linkages are set up tight enough so that they will frictionally hold the parts and hence the window in any intermediate position or in the fully opened position.

When the device is used for operating casement Windows, it may be mounted on the left or right sides of the only one linkage pair. This mode of installation is illustrated in Figures 12 and 13, where only the left linkage In addition, the bar 30 is discarded and a fixture 65, having a pivot pin 66 thereon is provided on the bottom of the swinging casement sash CS. The linkZSL is flexed so that it will press down on the pivot 66, yet it can spring up so as to be released, if so desired. 7

In this mode of operation the linkages are balances except for the bent levers 57B and 57T which is consequently unloaded on one side. Any cocking of these bent levers is prevented, however, by the sliding of pins 52 and 56L and 56K in the slots 418, MT and 41U, respectively, which causethe bent levers always to move as in a translatory motion.

. The operating mechanism of the present invention may be used foroperating round, oval or other odd shaped windows.

As many variations in mode of construction of the apparatus herein illustrated and described will suggest thema We claim:.

1. A closure operator comprising a frame, an arm mounted on an arm pivot on the frame and extending therefrom for swinging movement relative to said frame, a manual member pivotally mounted on the frame for oscillatory rotation through less than one complete turn about an axis generally parallel to but spaced from the arm pivot and link means eccentrically connected pivotally to said manual member and pivotally connected to said arm for swinging the arm as said manual member is rotated, and connection means having freedom of motion about an axis parallel to the arm pivot and in a plane normail to said axis by which said arm may be attached to said closure. 7

2. The closure operator of claim 1 further characterized in that apair of arms are mounted respectively on spaced parallel arm pivots on said frame and each extending. therefrom for swinging movement in opposite directions from a position .where they extend generally away from each other to a position in which they extend generally in the same direction, each of said arms being pivotally connected to said link means so as to be swung when said manual member is oscillatably rotated, and said connection means includes means pivotally:at tached respectively to each of said pair of arms.

3. The closure operator of claim .1 further .characterized in that said link means includes a member mounted on the frame for ,translatory oscillation as said manual member is oscillated; i a 4. The closure operator of claim 1 further characterized in that said, arm is composed of duplicate elements inspaced superimposed position and said link means includes an element positioned between, them and connected to said elements by means of a pivot having an axis parallel to and spaced from said arm pivot.

5. The closure operator of claim 1 further characterized in that said arm is composed of duplicate elements in spaced superimposed position and said connection means includes a radius strip extending between the ends of said duplicate elements and pivotal therewith at a common pivot.

6. The closure operator of claim 1 further characterized in that said connection means includes a hook element adapted to be secured to the closure which is to be operated and a keeper shaped to be detachable from the hook element only when the closure operator and closure are operated to position said closure in at least a partially opened condition.

7. The closure operator of claim 1 further characterized in that said arm has more stiffness against deflection when moved in a plane thru said arm than when moved out of said plane. 7

8. A closure operator comprising a frame composed of superimposed frame plates each of which has a projecting portion having a pivot hole therein, a support plate having a slot therein for snugly receiving the projecting portions of said plates in a normal direction therethru for thereby supporting said frame plates spaced from each other in parallel superimposed position, said projecting portions being of sufiicient length so as to extend sufiiciently beyond the support plate after passing therethru so as to locate said pivot hole at a position removed from said support plate, an additional spacer element between said plates at a position spaced from said support plate for additionally supporting said frame plates in spaced parallel condition, a rotatable cylinder having a slot formed therein transverse to the axis thereof, said cylinder being mounted for rotation on said projecting portions on an axis normal thereto, an op erator handle mounted on said cylinder for manually oscillating it, an additional pivot extending through said frame plates on that portion thereof which is on the opposite side of said support plate from said cylinder, an arm extending in between said frame plates and pivotally journalled on said additional pivot, at least a portion of said arm extending well beyond said frame plates and having securing means at the outer end thereof by which it is adapted to be loosely secured to a closure for moving it, and link means having one end eccentrioally connected pivotally to said cylinder and extending through said support plate and connected by pivot means to said arm at a point along said arm removed from said additional pivot.

9. The closure operator of claim 8 further characterized in that said arm is composed of duplicate superimposed elements spaced from each other and said link means includes a portion extending between them and connected thereto by said pivot means.

10. The closure operator of claim 8 further characterized in that said frame plates each are provided with slots which are located so as to be aligned when the frame plates are superimposed and said link means includes a slider positioned between said frame plates and bearing means normal to said slider and extending into said slots for restraining said slider from all but substantially translatory motion, said slider being connected by a first means to said cylinder and by a second link to said arm.

11. The closure operator of claim 10 further characterized in that said slider and arm each are composed of duplicate superimposed pairs of elements in spaced planes, said first link is situated in the space between said spaced planes.

12. The closure operator of claim 8 further characterized in that right and left arms are provided and disposed on said frame in symmetrical arrangement on opposite sides of a theoretical centerplane through the axis of said cylinder and substantially normal to the plane of the closure with which the device is used, when said closure is in closed position, each said arm being pivoted similanly .upon a pivot through the frame and each being connected by said link means to said cylinder so as to be radially oscillatable from one limiting position in which said arms extend outwardly from said theoretical centerplane to another limiting position in which they extend generally along opposite sides of said centerplane, and said securing means includes long links pivotally attached respectively to the outer ends of said arms said long links being pivotally connected by a securing element.

13. The closure operator of claim 8 further characterized in that said support plate has an aperture therethru sufiiciently large so as to permit the link means to oscillate sideways as it is moved, and a thin slide plate is provided against said support plate for covering said aperture, said slide plate being provided with an aperture snugly receiving said link means which is passed therethru, said slide plate being shaped so as to be movable sideways back and forth as the link means is operated therethru.

14. The combination with a window frame and a window mounted to move between open and closed conditions with respect to said frame; of a window operator including a support plate mounted in said frame, a crank rotatably mounted on a central first axis thereof on said support plate, means for rotating said crank, an operator link pivotally mounted on said crank about a second axis parallel to and spaced from said central first axis, said support plate being provided with an operator-cross link slot extending radially outwardly from said central axis and a cross-connector slot spaced from and parallel to said operator-cross link slot, a cross link, an operatorcross link pin riding in said operator-cross link slot and pivotally connecting said operator link to said cross link, a connector link, a cross-connector link pin riding in said cross-connector slot and pivotally connecting an outer end of said cross link to said connector link, an operator arm pivotally mounted on said support plate and pivotallyv connected to said connector link, a connector-arm pivotally connected to said operator arm, and means for attaching said connector arm to said window.

15. The combination with a window frame and a window mounted to move between open and closed conditions with respect to said frame; of a window operator including a support plate mounted in said window frame, a crank rotatably mounted on a central axis thereof on said support plate, means for rotating said crank, an operator link pivotally mounted on said crank about an axis parallel to and spaced from said central axis, said support plate being provided with an operatorcross link slot extending radially outwardly from said central axis and a pair of cross-connector link slots spaced equal distance from, parallel to and on opposite sides of saidoperator-cross link slot, a cross link, an operator-cross link pin riding in said operator-cross link slot and pivotally connecting said operator link to said cross link, a pair of connector links, a pair of cross-connector link pins each riding in one of said cross-connector link slots and pivotally connecting outer ends of said cross link to one of said connector links, a pair of operator arms each pivotally mounted on said support plate and each pivotally connected to one of said connector links a pair of connector arms each pivotally connected to one of said operator arms, and means for attaching each of said connector arms to said window.

16. The combination as specified in claim 15 wherein said operator link, said connector links and said connector arms lie in a single plane, and said cross links and operator arms each consist of separate identical upper and lowermembers adjacent links and arms which lie in said single plane.

17. The combination as specified in claim 16 wherein said support plate includes spaced apart, parallel upper and lower members each of which are provided with an operator-cross link slot and with cross-connector link 180 degrees, a handle for rotating said crank, an operator link pivotally mounted on said crank about a second axis parallel to and spaced from said first axis, said support plate being provided with an operator-cross link slot extending radially outwardly from said first axis and a pair of cross-connector link slots equal distance from, parallel to and on opposite sides of said operator-cross link slot, a cross link, an operator cross link pin riding in said operator-cross link slot and pivotally connecting said operator link to said cross link, a pair of connector links, a pair of cross-connector link pins each riding in v one of said cross-connector link slots and pivotally connecting outer ends of said cross link to one of said connector links, a pair of operator arms each pivotally mounted on said support plate and each pivotally connected to one of said connector links, a pair of connector arms each pivotally connected to one of said operator arms, an eye member pivotally connected to each of said connector arms and a hook member mounted on said window and removably mounted in said eye member.

19. The combination as specified in claim 18 wherein rotation of said crank causes said second axis to rotate about said first axis at a side of a radial plane extending outwardly from said first axis and containing a longitudinal axis of said operator-cross link slot as said window moves from open toward closed condition, the relationship of the parts being such that said eye member contacts at least one of said connector links and cross links in advance of said second axis reaching position in said radial plane, and wherein further rotation of said crane after said eye member makes said contact causes said second axis to move to position at a second side of said radial plane against the resilience of said connector and operator arms.

References .Cited in the file of this patent UNITED STATES PATENTS Thoma Jan. 2, 1940 

